Yield monitor systems are used to measure crop yields during harvesting. Yield characteristics, such as weight or moisture content, are used to assess the quality and quantity of a crop and accordingly determine its purchase price. In one example, a yield equation is used that assesses the quality and quantity of a crop is based on four distinct variables and a fifth related variable. The four variables include volume, temperature, moisture, and test weight (density) of the harvested crop. The fifth related variable is the weight of the harvested crop, and with at least some yield monitors the weight is determined according to the volume and an assumed test weight.
There are a number of mechanisms to measure crop weight. In one example, an impact plate is used to measure an impact force of harvested crop thrown against the impact plate when exiting a crop chute of a harvester elevator. The measured impact force is conditioned and converted into a harvested crop weight.